Clutch.



W. E. BARNARD.

CLUTCH.

APPLICATION FILED 001228, 1912.

1 90,444. Patented Mar. 17, 1914.

' This rebounding on TED srarns PATENT OFFICE.

Warren E. nannann, or HARTFORD, connnc'rrcur, ASSIGNOR 'ro JOHNunmannwear, or BROOKLYN, new roan Specification or Letters nan. t t 17,1914,

To all whom it may concern: Be it known that I, WALTER E. BARNABD, acitizen of the United States, residing in Hartford, in the county ofHartford and State of Connecticut, have invented certain new and usefulImprovements in'Glutches, of which the following is a specification.

My invention relates toimprovements in clutches, such for instance asdisclosed in my application N0.707,153, filed July 2, 1912, and used inconnection with a typewriter-computing machine of the. master wheelclass. In machines of this class, nor;

mally open clutches are individually closable by the numeral keys. Theseclutches are connected respectively to. mutilated gears having teethcorresponding respectively with the numeral keys; as for in stance, the1 key controls the gear havin g one tooth; the 2 key controls the gearhaving two teeth, etc. When the clutch makes "a revolution, its gearengages a train of gearing whose, movement is carried by means of themaster wheel into a totalizer. It isdesirable to use an instantlygripping clutch to avoid any loss of time between the depression of thekey and the operating of the computin mechanism. The clutch itselfpreferably comprises a'constantly rotating member contained in a cup, inwhich is housed a grippin ball or roll to connect the cup to the rotatmgmember. At a high speed, there isapt to be a rebound of the clutch whenarrested at the conclusion ofits stroke; such arrest being caused by astop which is moved into the path of a rojection of said clutch, andwhich also re eases the clutch. As the clutch rebounds, it automaticallycloses again, and accordingly is reversed and strikes the stop a secondtime continues and causes the clutch to chatter.

The object of the inventiongisgto prevent the reboundof the clutch. 1

In typewriter,- computing machines of this type, an instantly grippingclutch 1s figure before the last one has been entirely.

computed in its proper column. The clutc time between the used to avoidany loss 0 of the depression of the key and the closing clutch to effectthe computation, sirable to complete the computation before laten,inorder that the type strikes the p there may be no possibllityofwriting a new marked 1 controls aclutch having a as 1t is de-Application and time. a, 1912'. Ser1a1No.728,034.

generally comprises a cup in which a gripping member is controlled sothat it may grip a rotating shaft at will, to cause the clutch cup torotate, and will be more clearly described in the annexed specification.

In the accompanying drawings, Figure 1 shows a sectional view of aclutch with my improvement attached. Fig. 2 shows the clutch closed andstarting it to revolve.

Fig. 3 is aperspective showing the assemblin of the clutch.

T e clutch consists of a casing 1 surrounding a constantly rotatingshaft 2, and a ring ,3 in said casing provided with a recess 4 to holdand control a grippin roll 5 between the casing 1 and shaft 2. ormallythe roll 5 is held loosely ina depression 6 in the inner side of thecasing 1, so that shaft 2.

may rotate freely. When the roll 5 is advanced, however, (in thedirection of the arrow in Fig. 2) it will become jammed between thecasing 1 and shaft 2, owing to the convergence of the depression 6 withthe inner surface of the casing, and thereby cause said casing and shaft.to rotate together. To hold this clutch normally open, a stop 7 isarranged inthe path of a projection 8 from the ring 3, and holds backsaid rin against the tension of'a spring 9, so that t e roll 5 is keptin the depression 6.

A mutilated gear 10 is carried on the periphery of the clutch casing 1to engage a pinion 11 arranged to drive the master wheel of thecomputing machine. The number of teeth on said mutilated gear variesaccording to the numeral key controlling the clutch, as for instance,the key usually gear with one tooth; the key usually marked 2 controls aclutch having a gear with two teeth, etc.

.The shaft 2, which rotates the clutch casings 1, is driven at highspeed in order that the computation be completed. promptly;

but, when the clutch casings rotate so rapidly be considerable. rebound.Whenthe casing 1 rebounds, the spring 9 causes the gripping roll'5 tolock or close the clutch again, only to strike the releasing stop 7again. The

repeated opening and closing 'of the clutchproduces a disagreeablechattering noise.

In computing machines, the load on differand strike the stop 7 there isapt to 1 wheel through ten digit s aces than through only one or two. Ina ditionto this, the

ent clutches. variesivery much with the individual clutch, because,'as'has been stated, the number of teeth 10 is proportional to.

,the digit represented by the numerali'key deg; pressed, and obviouslythereis much more load on the clutch in turninga computing load on eachindividual clutch will vary greatly because at some times a long stringof 9s will have 1- added to them, thus causing every one of said 9s tobe turned to read 0 viz., to carry over. This carry over turningrequires great power. The result, therefore, will be that the lightmotor" Hwhieh is commonly employed in computing machines will bematerially slowed by the heavier loads on the clutches, and thereforethe stop 7 will be struck by the projection 8 sometimes when the clutchis turning very rapidly and sometimes when the clutch is turning at avery low speed compared with the normal speed. Since the clutch properis arrested by the spring'9 when the pro ection 8 strikes the stop 7,the result will be that at varying speeds the clutch proper will come torest at diiferent points, because sometimes the arresting of the clutchwill compress the spring 9 to one extent and sometimes to another. Tomeet these varyiiig conditions, the clutch is provided with a pluralityof teeth 13 to prevent any backward motion whatsoever, no matter in whatposition the clutch may be when the spring 9 finally brings it to rest.This prevention of the backward rotation of the clutch and theholdin ofthe projection by the stop 7 positively hold the dog carrier 3. so thatthe clutch isreleased. Were it notifor the p1u rality of teeth 13,- theclutch sometimes would reboimd sufliciently to cause the grip-- .pingroll 5 to look again and thus injure the machine. The dog-12 may rideonthe peripheryof the casing during the revolut on of the clutch, when notin engagement with the teeth.

Variations'may be resorted to within the (scope of the invention, andportions of the improvementsmay be used without others.

Having thus described my invention, I claim: i r

1. The combination with a shaft forming a driving member, of a drivenmember encircling said shaft, a normally ineffective dog adapted to locksaid shaft to said driven member, a dog-carrier loose on said shaft, :1

projection on said carrier, a' spring between projection on said dogcarrier extending bc- I yond said driven member, a stop for holding saiddog carrier by said projection in ineffective position, a spring betweensaid projection and said driven member tending to throw said carrier tocause its roll to glll) and whereby the clutch is arrested after arevolution, a plurality of teeth on said driven member, and'a pawladapted to cooperate with said teeth to hold said driven member in anyposition it is arrested withthe spring compressed between theIn-ojectionand the driven member. I

WALTER E. BARN ARD. I

Witnesses:

J ULIUs DUcKsrmE, Trrus H. IRONS.

